Re: Dana 60 or 14(FF)
Ok, first, FrankP, The lowest gears you can go with a 14bolt is 5.13.
Now, what years did the Dana 60's come out of??
I'm 99% sure you will have to move the perches and shock mounts to bolt that D60 rear axle in. B/c most if not all GM rear D60s are found in the 72' and earlier 1ton or 3/4 ton P/Us.
Second, the 14bolts (if out of a 3/4 ton) will either ahve 3.73 or 4.10 if stock, but will bolt right in. The 14bolt is by far stronger and even better than the Dana 70 rear in my opinion. The only thing the 70 rear has over the 14bolt is the 35splined shafts VS the 14bolts 30spline shaft. No biggie though, they're both 1.5" shafts. 14bolt has a bigger R & P though and other stuff too. Oh, but, also, make sure you have the 35spline shaft version D70, b/c not all came with that. Some had like, I forget, but I think it was 19 or 17 spline shafts. Anyhow, no worries with the 14bolt, they all had 30spline 1.5" shafts. Too much confusion with the D70 rear.
Ok, some 14bolts do come with 4.56 gears stock though. But they're usually found in some 1 ton versions (and all 1.25 ton CUCVs) version 14bolts. With the CUCV version 14bolt you'll get the detroit in the rear stock. BUT, with the 1 ton version 14bolt (and CUCV's for that matter, which is exactly the same as 1ton version, but has 4.56 and detroit), you will have to move the spring perches and shock mounts to make it work in your truck. Hope I didn't confuse anyone.
89' 1 TON of FUN K5